Digital security multimedia sensor

Abstract

A fully digital camera system provides high-resolution still image and streaming video signals via a network to a centralized, server supported security and surveillance system. The digital camera for collects an image from one or more image transducers, compressing the image and sending the compressed digital image signal to a receiving station over a digital network. A plurality of image transducers or sensors may be included in a single camera unit, providing array imaging such as full 360 degree panoramic imaging, universal or spherical imaging and field imaging by stacking or arranging the sensors in an array. The multiple images are then compressed and merged at the camera in the desired format to permit transmission of the least amount of data to accomplish the desired image transmission. The camera also employs, or connects to, a variety of sensors other than the traditional image sensor. Sensors for fire, smoke, sound, glass breakage, motion, panic buttons, and the like, may be embedded in or connected to the camera. Data captured by these sensors may be digitized, compressed, and networked to detect notable conditions. An internal microphone and associated signal processing system may be equipped with suitable signal processing algorithms for the purpose of detecting suitable acoustic events and their location. In addition, the camera is equipped with a pair of externally accessible terminals where an external sensor may be connected. In addition, the camera may be equipped with a short-range receiver that may detect the activation of a wireless ‘panic button’ carried by facility personnel. This ‘panic button’ may employ infrared, radio frequency (RF), ultrasonic, or other suitable methods to activate the camera's receiver.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention is a continuation of co-pending patent application Ser. No. 09 / 593,361, filed Jun. 14, 2000 “Digital Security Multimedia Sensor.” The subject invention is generally related to digital cameras and sensors and is specifically directed to a multimedia sensor of use in connection with a digital networked surveillance system. The subject invention in it's preferred embodiment is a networked appliance. [0003] 2. Discussion of the Prior Art [0004] Security of public facilities such as schools, banks, airports, arenas and the like is a topic of increasing concern in recent years. Over the past few years, a number of violent incidents including bombings, shootings, arson, and hostage situations have occurred. In addition, agencies responsible for public security in these facilities must cope with more commonplace crimes, such as drug dealing, vandalism, theft and the like. [0005] Such facilities frequently empl...

AI Technical Summary

Benefits of technology

[0029] In addition, the communication protocols used by the network and attachments thereunto embed addressing and routing information into the individual signals. This allows the digital information, produced by the attached cameras, to be efficiently routed and disseminated. An example of this protocol is TCP / IP, commonly used in the Internet.

[0030] An advantage of such a network and protocol is that the audiovisual signals, produced by the various cameras, may be accessible by any suitable terminal attached to the network. In particular, cameras are accessible by Internet Browsers and search engines. This is an advantageous contrast to the prior art, where the audiovisual signals produced by the cameras were viewable only on a centralized monitoring station.

[0031] As a further refinement, enhanced communications protocols may be employed, which provide more efficient transport of real-time asynchronous signals such as the audiovisual signals produced by the various cameras. Protocols such as Real-Time Protocol (RTP), Real Time Control Protocol (RTCP), IP Multicast Protocols, and others, may be used to reduce overall network bandwidth and provide reliable delivery of the audiovisual data to one or more client recipients.

[0032] As a further refinement, the digital networking system used may be a wireless network. Such a network would be of advantage in older institutions where the cost of adding network cabling might be prohibitive or hazardous. Wireless networking also allows cameras or monitoring stations to be mobile. A camera might be temporarily installed in some location for special events, without the time and expense of adding network cabling. Or, a facility guard, on foot, may be able to select and view any particular camera during his rounds.

[0033] As a further refinement, the various cameras may synchronize themselves to a master clock using a suitable protocol, such as NTP or SNTP. Over a localized network within a facility, camera time bases may thus be synchronized to within 1 to 10 milliseconds of a master clock. This is advantageous during an event reconstruction, where recorded images or videos from the vantage point of different cameras may be compared. Such camera-to-camera synchronization may also be used for accurately measuring time-of-arrival differences between cameras, thereby allowing the location of said event to be calculated using well-known triangulation techniques.

[0034] As a further refinement, an internal data storage device such as a small disk drive may be embedded into the camera. This allows the camera to collect images and / or video and audio from cameras, which may be located at some inaccessible distance from the facility's data network. Stored images or video & audio may be later retrieved for analysis or archival, either by removal of the storage media or by transfer of the stored data over the network.

Problems solved by technology

Over the past few years, a number of violent incidents including bombings, shootings, arson, and hostage situations have occurred.

These prior-art systems often use technologies that are somewhat dated.

The sensors are not ‘networked’ in the modern sense; they are generally hard-wired to the centralized monitoring system via a ‘current loop’ or similar arrangement, and do not provide situational data other than their ON / OFF status.

Video systems in common use today are particularly dated—they are generally of low quality, using analog signals conveyed over coaxial or, occasionally, twisted-pair cabling to the centralized monitoring facility.

Further, such systems generally do not have the ability to ‘share’ the captured video, and such video is generally viewable only on the system's control console.

In each case, the video is subject to degradation due to the usual causes—crosstalk in the wiring plant, AC ground noise, interfering carriers, and so on.

Due to the bandwidth constraints imposed by the public-switched telephone system, such systems are typically limited to low-resolution images, or to low frame rates, or both.

Each of these prior-art systems suffers functional disadvantages.

The composite video / coaxial cable approach provides full-motion video but can only convey it to a local monitoring facility.

The low-bit rate approach can deliver the video signal to a remote monitoring facility, but only with severely degraded resolution and frame rate.

While useful, this approach lacks the functional flexibility possible with more modern networking technologies.

Images